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The network confirms that "Walking Dead" writer Glen Mazzara will take over for showrunner Frank Darabont and that the show will not miss its Oct. 16 premiere date.

Fans of The Killing will find out who killed Rosie Larsen in season two. That promise came from AMC’s head of original programming Joel Stillerman, who admitted that the network did not effectively “manage expectations.”

The series starring Billy Campbell and Mireille Enos hooked viewers into a moody mystery surrounding the death of teenager Rosie Larsen with suspicion falling on the slick politician (Campbell) and her parents (Michelle Forbes and Brent Sexton). The show’s promotional tagline was: “Who killed Rosie Larsen?” But viewers were up in arms when the final episode ended on a rather ambiguous note.

“For everybody who was frustrated, we hear you,” said Stillerman, addressing reporters gathered at the Beverly Hilton for the semi-annual Television Critics Association press tour.

“We would have taken a different approach to managing the expectations about what was going to happen,” said Stillerman. “It was never intentionally meant to mislead anybody. Our goal was to create a brilliant piece of character-based story telling and to try to do something [different]. We think we got there but we definitely didn’t manage expectations the way they should have been managed.”

“I can say definitively,” added Stillerman. “You will find out who killed Rosie Larsen in season two.”

Stillerman also addressed the future of The Walking Dead, which earlier this week saw showrunner Frank Darabont step down to be replaced by writer and executive producer Glen Mazzara.

The Walking Dead – which in its first season became AMC’s most-watched original series – is scheduled to bow its second season Oct. 16. And Stillerman noted that the show is on track to make that date.

“I can report that production is not go to miss a beat and we’re going to make our air date,” said Stillerman. “What I’ve seen [so far] and what I’ve seen coming down the pike, we’re going to take what we started last year and really move it to the next level. It’s going to be an incredible season.”

Stillerman thanked Darabont for his considerable contributions. “He wrote [and] directed a brilliant pilot and his fingerprints are all over [creator] Robert Kirkman’s source material and we’re incredibly grateful for his contributions.”

But he would not address why Darabont stepped down, though speculation has centered on Darabont’s comfort level with the daily grind of running a television program after spending the majority of his career in film.